your post implies digg isn't a startup.
Evidently Digg is better at the monetization game than Reddit has been, so more sales staff I can understand... but devs?
Personally I have no idea nor do I see any reason for that many people working for digg, but my understanding is that Digg (or rather Kevin Rose) has always been about having the perception of big without actually being that big.
Personally, I don't consider Digg a startup.
Unless you are owned by a larger company that runs you at a loss as part of their strategy. Or stragedy.